Ice making machine and method of controlling an ice making machine

ABSTRACT

An ice forming apparatus capable of forming ice pieces is provided, including, a transfer zone between the ice forming apparatus and a storage area, and an ice sensing apparatus configured to both detect migration of the ice pieces through the transfer zone and to detect build-up of the ice pieces in the transfer zone. The ice forming apparatus is preferably an auger-type device, such as a flaker-type or a nugget-type device.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This patent application claims the benefit under 35 U.S.C. § 119(e) ofU.S. provisional patent application Serial No. 60/689,387, filed Jun.10, 2005, which is hereby incorporated by reference.

BACKGROUND 1. Field of the Invention

The present invention relates generally to an ice making machine and amethod of controlling an ice making machine. More particularly, theinvention relates to an ice making machine having an ice sensingapparatus for the detection of ice pieces and a method of controllingthe ice making machine based on the detection. Although the presentinvention is related to all types of ice making machines, it isparticularly suitable for use in an auger-type ice making machine, suchas a flake or a nugget making machine. 2. Related Technology

In a conventional auger-type flake ice making machine, an ice formingapparatus includes an ice making chamber that is cooled to a relativelylow temperature by a cooling fluid, such as refrigerant. Water isdelivered to the ice making chamber and contacts the wall of the icemaking chamber to form ice. Furthermore, an auger is positioned withinthe ice making chamber and has an auger flight with a diameter slightlyless than that of the ice making chamber wall. Therefore, as the augerrotates, the auger flight removes portions of the ice from the chamberwall and transports the ice in the upward direction towards an openingin the top of the ice making chamber. The ice is expelled from theopening and migrates towards an ice storage bin, where it is storeduntil removed for consumption. More particularly, the storage bin istypically located below the top of the ice making chamber so that theice pieces naturally fall through or slide along a transfer zone, suchas an ice chute.

Ice making machines currently include a control system to ensure thatall of the various ice-making components are properly functioning. Moreparticularly, the control system measures system conditions to preventpossible damage to the system components, such as the auger, the augermotor, and the ice making chamber.

One such control system, disclosed in U.S. Pat. No. 6,463,746, measuresthe current in the auger motor during ice-making to prevent potentialdamage to the ice producing machine. For example, if the current flowthrough the motor exceeds a predetermined threshold, the systemcompressor is turned off. However, this system may not be able to detectother types of system failures, such as a failure to reach or maintainan effective ice-making temperature in the chamber.

A similar control system to the one described above is an auger rotationsensor disclosed in U.S. Pat. No. 6,609,387. A sensor is coupled withthe inner surface of the ice making cylinder and a magnet is coupled tothe auger rotating within the cylinder. The sensor and the magnetcooperate to detect abnormal rotation of the auger. However, as with theabove-described design, this control system fails to detect failuresother than those relating to the rotation of the auger.

Another control system, disclosed in U.S. Pat. No. 6,601,399, measuresthe rate of water consumption by measuring the water level in thereservoir over a period of time. If the water is not consumed at aminimum threshold rate, a controller adjusts the capacity of thefreezing circuit. However, as with the other known designs, this systemonly detects a particular type of system failure and is not able todetect if ice is actually being produced.

In addition to failing to detect if ice is being produced, the abovecontrol systems fail to detect the ice level within the storage bin.Therefore, additional sensors are required to detect when a desiredamount of ice is in the storage bin, while preventing an undesirableoverflow condition in the storage bin or in a transfer zone connectingthe ice forming apparatus to the storage bin.

One type of ice level detector, which is disclosed in U.S. Pat. No.5,172,595, is an ultrasonic sensor that is positioned at a top portionof the storage bin. In this design, once the ice sensor detects icepieces at a relatively high threshold level in the storage bin, acontroller deactivates the compressor and prevents the formation of iceuntil some of the ice is removed from the storage bin and the ice dropsbelow the threshold level. However, the optical sensor is unable todetect normal ice migration from the ice maker and therefore cannot beutilized to determine whether the ice maker is functioning properly.

Another type of ice level detector, which is disclosed in U.S. Pat. No.5,142,878, includes a movable detection plate 32 b mounted at the top ofa vertical delivery chute 31 that leads to a storage bin 41. When thestorage bin 41 becomes filled and the ice pieces accumulate within thedelivery chute 31, the ice pieces cause displacement of the detectionplate 32 b, thereby opening a proximity switch and stopping the icemaking process. However, the detection plate is only displaced when theice pieces accumulate in the delivery chute; not when ice pieces migratethrough the delivery chute 31 during normal ice making. Therefore, thedetection plate is unable to detect normal ice migration from the icemaker and therefore cannot be utilized to determine whether the icemaker is functioning properly.

Yet another type of ice level detector, which is disclosed in U.S. Pat.No. 5,390,504, includes a switch assembly 20 mounted at the top of ahorizontal discharge passage and a movable detection plate 15 c mountedat the top of a vertical delivery chute 14. Both the switch assembly 20and the detection plate 15 c are configured to be displaced byaccumulated ice within the horizontal discharge passage and the verticaldelivery chute 14, respectively. However, due to their location at thetop of the horizontal discharge passage and the vertical delivery chute14, the switch assembly 20 and the detection plate 15 c are unable todetect normal ice migration from the ice maker and therefore cannot beutilized to determine whether the ice maker is functioning properly.

It is therefore desirous to provide an improved, low cost, simple icemaking machine, and an improved method of controlling the machine, so asto reduce the risk of damage to the auger, the auger motor, and the icemaking chamber, and to achieve and maintain a desired ice level in thestorage bin.

SUMMARY

In overcoming the limitations and drawbacks of the prior art, thepresent invention provides an ice making machine including an iceforming apparatus capable of forming ice pieces, a transfer zone betweenthe ice forming apparatus and a storage area, and an ice sensingapparatus configured to detect at least some of the ice pieces duringthe migration of the ice pieces through the transfer zone.

In one aspect of the invention, the ice sensing apparatus furtherdetects a build-up of the ice pieces in the transfer zone. Furthermore,the ice sensing apparatus in this design may include a movable portionhaving a first position corresponding to the migration of the ice piecesand a second position corresponding to the build-up of the ice pieces inthe transfer zone. The ice sensing apparatus in this design may alsoinclude a first sensor to detect the first position of the movableportion and a second sensor to detect the second position of the movableportion.

In another aspect, a method of controlling an ice making machine isprovided, including the steps of: a) forming ice pieces with an iceforming apparatus, b) permitting migration of the ice pieces from theice forming apparatus through a transfer zone to a storage area; c)detecting at least some of the ice pieces migrating through the transferzone; and d) deactivating the ice forming apparatus if no migrating icepieces are detected within a predetermined time period.

The above aspects of the present invention therefore permit monitoringof the ice-making operation to provide a simple, low cost design fordetecting the migration of ice pieces through the transfer zone; therebyreducing part complexity and cost of the ice making machine.

In yet another aspect of the present invention, the ice formingapparatus includes an outlet section that cooperates with the transferzone to at least partially define a clean zone. The ice sensingapparatus includes a first portion located within the clean zone and asecond portion positioned outside of the clean zone. This aspect of thepresent invention reduces the amount of moisture that is exposed to thesecond portion, thereby improving the performance and the effective lifeof the sensor components.

Further objects, features and advantages of this invention will becomereadily apparent to persons skilled in the art after a review of thefollowing description, with reference to the drawings and claims thatare appended to and form a part of this specification.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an isometric view of an ice making machine embodying theprinciples of the present invention and including an ice formingapparatus and an ice chute extending to the inlet of an ice storagearea;

FIG. 2 is an enlarged, isometric view of the ice making machine and theice chute shown in FIG. 1, having various components removed therefromfor clarity purposes;

FIG. 3 is a cross-sectional view of the ice chute taken along line 3-3in FIG. 2, showing an ice sensing apparatus coupled with the ice chute;

FIG. 4 a is an enlarged view of the ice chute in FIG. 3, where the icesensing apparatus is in a first position, indicative of migration of icepieces down the ice chute;

FIG. 4 b is an enlarged view similar to that shown in FIG. 4 a, wherethe ice sensing apparatus is in a second position, indicative of abuild-up of the ice pieces in the ice chute;

FIG. 5 a is a flowchart showing a method for operating an ice makingmachine during a normal operation mode;

FIG. 5 b is a flowchart showing a method for restarting an ice makingmachine after a safety shutdown has occurred;

FIG. 6 is a top view of a water reservoir shown in FIG. 1;

FIG. 7 is a side view of the water reservoir shown in FIG. 6;

FIG. 8 is a front view of the water reservoir shown in FIG. 6;

FIG. 9 is an enlarged cross-sectional view taken along line 9-9 in FIG.3, showing a portion of the ice sensing device; and

FIG. 10 is an exploded view of the auger and the casing of the iceforming apparatus shown in FIG. 1.

DETAILED DESCRIPTION

The present invention will now be further described. In the followingpassages, different aspects of the invention are defined in more detail.Each aspect so defined may be combined with any other aspect or aspectsunless clearly indicated to the contrary. In particular, any featureindicated as being preferred or advantageous may be combined with anyother feature or features indicated as being preferred or advantageous.

Referring now to an embodiment of the present invention, FIG. 1 shows anice making machine 10 generally including an ice forming apparatus 12capable of forming ice pieces, a storage area for storing the ice pieces(represented by an inlet tube 53 and an ice bin 14, which is shown inphantom lines), a transfer zone, such as an ice chute 16, for deliveringthe ice pieces to the storage area, and an ice sensing apparatus 18configured both to detect the migration of the ice pieces along the icechute 16 and to detect the build-up of the ice pieces in the ice chute16.

The ice making machine 10 includes components of a refrigeration systemthat promotes heat exchange between a circulating fluid, such as arefrigerant, and the ambient air. As is well known in the art, gaseousrefrigerant is drawn into a compressor 11, which causes an increase inboth the pressure and temperature of the refrigerant. Exiting thecompressor 11 in a gaseous phase, the refrigerant is then condensed intoa liquid phase by a condenser 13. More specifically, a condenser fan 15forces ambient air across heat exchange tubes 17 within condenser 13,thereby cooling the refrigerant flowing through the heat exchange tubes17. Next, the refrigerant flows through an expansion valve (not shown),which causes the refrigerant to expand into a low-pressure,low-temperature mixture of gas and liquid. The mixture of gas and liquidthen flows into an evaporator section (not shown) of the ice formingapparatus 12 and cools an ice making chamber 20 (as shown in FIG. 10) toa freezing temperature that is preferably close to or below 5 degreesFahrenheit (−15 degrees Celsius).

As shown in FIGS. 2 and 10, a heat exchange tube 22 carrying therefrigerant is utilized for cooling the ice making chamber 20. Morespecifically, the heat exchange tube 22 extends into the ice formingapparatus 12 near a lower portion of the ice making chamber 20, coilsaround a housing defining the ice making chamber 20, and exits the iceforming apparatus 12 near an upper portion of the ice making chamber 20.The coiled portion of the heat exchange tube 22 is surrounded by acasing 24 for insulative and protective purposes. The casing 24 ispreferably made of metal, such as a tin-based solder.

Referring back to FIG. 1, ice making water is delivered from a waterreservoir 26 to a lower portion of the ice making chamber 20 via asupply tube 28. The ice making water is preferably delivered to the icemaking chamber 20 via natural flow forces. The ice making watertypically fills the ice making chamber 20 to the same level as the waterreservoir 26.

Furthermore, as shown in FIG. 10, an auger 30 is positioned within icemaking chamber 20 and includes a generally spiral-shaped auger flight32. The auger flight 32 has a diameter that is slightly less than thediameter of the ice making chamber 20 so that the auger flight 32removes most of the ice build-up from the ice making chamber 20 wall.For example, the auger flight diameter is preferably between 0.001 and0.01 inches smaller than the ice making chamber diameter so that all buta thin layer of ice is removed from the ice making chamber wall when theauger 30 rotates. An auger motor 33 rotates the auger 30, via an augerdrive gear system 35 (FIG. 1), in a direction so that the flightgenerates a lifting motion. As mentioned above, the ice making chamber20 is generally filled with water along the length of the auger 30 sothat the water adjacent to the ice making chamber wall is frozen intoice crystals. Therefore, as the ice crystals are being formed, therotating auger flight 32 scrapes the layer of ice from the inner surfaceand transports the newly-formed ice in the upward direction.

Next, as shown in FIG. 10, the ice is separated into pieces by an icecutting head 37 having a plurality of generally vertical blades 39. Theleading edge of each of the blades 39 preferably has a tapered portion41 to act as a wedge and split the ice into ice pieces 38 (FIGS. 4 a and4 b). The ice cutting head 37 shown in the figures is coupled to theauger 30 via a pair of bearings 43 so that the ice cutting head 37 doesnot rotate along with the auger 30. Based on the size and shape of thecutting head, the ice forming apparatus 12 can be used to form icepieces 38 into a desired shape and size.

Referring back to FIG. 2, the ice pieces 38 are then forced upwards pastthe ice cutting head 37 and through an opening 34 defined by the icemaking chamber 20 and the ice cutting head 37, where a rotating icewiper 36 sweeps the ice pieces 38 away from the opening 34. The icewiper 36, which includes a pair of projections 40 coupled to a bodyportion 42, is connected to the auger 30 such that the respectivecomponents 30, 36 rotate in unison with each other. The body portion 42has an arcuate, tapered underside surface that gradually urges the icepieces 38 in a radial direction out of the opening 34. The ice that isextruded through the ice cutting head 37 breaks into one of the icepieces upon contact with the underside of the body portion 42, therebyforming one of the ice pieces 38. Therefore, the distance between thetapered underside of the body portion 42 and the opening 34 controls thelength of the ice pieces 38. Furthermore, as the auger 30 and the icewiper 36 rotate, the projections 40 sweep the ice pieces 38 further awayfrom the opening 34.

Additionally, a nugget forming device (not shown) may be positioned atthe top portion of the auger 30 to compact the ice by forcing the icethrough generally small extrusion orifices. The compacted ice is thencut or broken into relatively small nuggets by an ice cutting componentwithin the nugget forming device. In addition to altering the shape andthe size of the ice described post-formation treatments squeeze outwater clinging to the ice, thereby causing the ice pieces 38 to have ahigher cooling capacity per pound of ice and increasing the coolingpotential of the ice pieces 38.

After being expelled from the ice making chamber 20, the ice pieces 38move through a transfer zone and into the ice storage area. The transferzone is defined by a path between the ice making chamber 20 and the icestorage area. For example, the transfer zone in the figures includes,but is not limited to, the area adjacent to the ice making chamberopening 34, a strainer 50 (which will be discussed in more detailbelow), and the ice chute 16.

The transfer zone is part of what is known as the food zone; the areathat often contains ice during normal operation of the machine. Forexample, in the figures, the food zone includes, but is not limited to,the following: the ice making chamber 20, the area adjacent to the icemaking chamber opening 34, the ice chute 16, and the storage bin inlettube 53 and the ice bin 14. Because the ice pieces 38 are typically usedfor consumption by people, National Sanitation Foundation guidelinesrequire that surfaces that potentially contact food are made of foodgrade materials. For example, a housing 45 defining the ice chute 16 andthe storage bin 14 is preferably formed by food grade plastic and theauger 30 and the inner surface of the ice making chamber 20 are formedby food grade metal.

For purposes of the present invention, a portion of the food zone isdefined as a “clean zone”. The clean zone 44 includes the outlet sectionof the ice forming apparatus and the transfer zone. Furthermore, aprotective lid 46 (FIG. 1) covers the ice chute 16 and the area abovethe ice making chamber opening 34 to prevent dust, dirt, and othercontaminants from entering the clean zone 44 (the protective lid 46 hasbeen removed in FIGS. 2, 4 a, and 4 b for illustrative purposes only).The protective lid 46 is also preferably constructed of food gradeplastic. Additionally, the protective lid 46 is preferably connected tothe housing 45 by a plurality of flanges 48 (FIG. 2) to preventcontaminants from entering the clean zone 44 and to prevent heatexchange between the ice pieces 38 and the ambient air.

As shown in FIG. 2, the strainer 50 is located between the opening 34and the ice chute 16 to prevent water, from melting ice, from flowingdown the ice chute 16. The strainer 50 preferably permits drainage ofwater into a water recirculation tube 52. More specifically, water flowsthrough the strainer 50, along the water recirculation tube 52, and backinto the supply tube 28 to be supplied to the ice making chamber 20.Alternatively, the water may be discarded or recirculated to a differentcomponent in the ice making machine 10. The strainer 50 has a slight,upward slope to further prevent water from flowing down the ice chute16.

After being formed in the ice making chamber 20, the ice pieces 38 areforced away by the ice wiper 36, across the strainer 50, and towards theice chute 16 by the rotating projections 40. For example, the ice pieces38 are initially directly contacted by the ice wiper 36 and are forcedonto the strainer 50. Next, due to the upward slope of the strainer 50,the ice pieces 38 do not typically migrate into the ice chute 16 bynatural gravity forces alone. However, subsequently-formed ice pieces 38that are expelled from the ice making chamber 20 force the ice pieces 38across the strainer 50 and into the top of the ice chute 16. The icechute 16 is generally downwardly-sloping so that the ice pieces 38 areable to naturally migrate down the ice chute 16 and are detected by theice sensing apparatus 18. After the ice sensing apparatus 18, the icepieces 38 migrate down a storage bin inlet tube 53.

The ice sensing apparatus 18 shown in the figures includes a contactmechanism, the movement of which is caused by engagement with the icepieces 38. For example, the contact mechanism includes a contact plate54 positioned along the path of migration of the ice pieces 38 such thatthe ice pieces 38 contact the contact plate 54 during migration towardsthe ice storage area. The contact plate 54 is pivotally supported via arod 56 that extends along an axis 58 and that is rotatably supported bya pair of saddles 60, sometimes known as bearings, on opposing sides ofthe housing 45. More specifically, the saddles 60 are relatively smooth,low friction surfaces conforming to the shape and the size of the rod 56such that a low friction seal 62 is formed by the respective components56, 60, to permit low-friction rotation of the rod 56 and the contactplate 54. The low friction seal 62 may also prevent some moisture frommigrating along the rod 56.

As best shown in FIG. 3, the rod 56 includes an enlarged-diameter collarportion 64 to prevent axial travel of the rod 56 and to reduce themoisture migrating along the rod 56 by forming an overlapped engagementwith the housing 45. The rod 56 preferably snaps into engagement withthe saddles 60 to prevent disengagement therefrom. However,alternatively, the protective lid includes a securing mechanism such asa tab with a semi-circular recess to prevent vertical displacement ofthe rod 56.

The contact plate 54 is located within the clean zone 44, and istherefore preferably made of a food grade material, such as food gradeplastic. Additionally, the contact plate 54 preferably includes one ormore slots 55 to permit water or small ice fragments to flow past thecontact plate 54 without causing the displacement thereof. When the icesensing apparatus 18 is not being moved by the ice pieces 38, thecontact plate 54 hangs generally vertically in a neutral position 57, aswill be discussed in more detail below.

At least one of the end portions of the rod 56 preferably extendsthrough the housing 45 and out of the clean zone 44. For example, afirst end portion 66 extends through a first side of the housing 45 anda second end portion 68 extends through the opposing side of the housing45. A signal member, such as an interrupting vane 70, is coupled to thefirst end portion 66 of the rod 56 such that the contact plate 56, therod 56, and the interrupting vane 70 rotate in unison with each other.The interrupting vane 70 in the figures is a generally thin, metal plateintersected by the rod 56. The interrupting vane 70 is positionedadjacent to a sensor device 72 that detects the position of theinterrupting vane 70, thereby determining the position of the contactplate 54.

As shown in FIG. 9, the sensor device preferably includes twoHall-effect sensors, including two magnets 74 a, 74 b facing a firstside of the interrupting vane 70 and two sensor elements 76 a, 76 bfacing a second side of the interrupting vane 70. In the figures, themagnets 74 are positioned on the inboard side of the interrupting vane70 and the sensor elements 76 are positioned on the outboard side, but areverse configuration may be used. In one design, the Hall-effectsensors have a supply voltage between 4.5 and 5.5 VDC filtered, at leasta 10 KΩ pull-down resistor connected from the output to the ground, anda nominal 10 nF noise capacitor connected from output to ground. Whenthe interrupting vane 70 is positioned between a magnet 74 and itssensor element 76, an electromagnetic field is disrupted and the sensorelement 76 sends a signal to a controller 78 (FIG. 1). Whether theinterrupting vane 70 disrupts the electromagnetic field between one,both or neither sets of the magnets and sensors 74, 76 indicates theposition of the interrupting vane 70 and the contact plate 54.

FIGS. 2, 3, and 9 show the interrupting vane 70 and the contact plate 54in the neutral position 57 so that the interrupting vane 70 interruptsthe electromagnetic field with two sets of magnets and sensors 74 a, 74b, 76 a, 76 b(causing the first and second sensor elements 76 a, 76 b tobe “closed”). The interrupting vane 70 and the contact plate 54 are inthe neutral position 57 when the forces acting thereon are negligible ornon-existent. More specifically, the interrupting vane 70 and thecontact plate 54 are typically in the neutral position 57 when no icepieces 38 are migrating along the ice chute 16.

FIG. 4 a shows migration 79 of the ice pieces 38 along the ice chute 16during normal ice making operation. More specifically, a relatively lownumber of ice pieces 38 are discharged from the ice making chamber 20and permitted to migrate towards the inlet tube 53 and ice storage bin14, thereby actuating the contact plate 54 forward into a first position80. When the contact plate 54 and the interrupting vane 70 are in thefirst position 80, the interrupting vane 70 is positioned between onlythe first magnet 74 a and the first sensor element 76 a of the sensordevice 72, thereby opening the first sensor element 76 a and indicatingto the controller 78 the position of the contact plate 54. In thisposition, the interrupting vane 70 defines a first angle 82 with thevertical direction. In other words, when the contact plate 54 iscontacted by the migration 79 of the ice pieces 38, the interruptingvane 70 pivots forward from the neutral position 57 by an amount equalto the first angle 82. After the ice pieces 38 migrate past the icesensing apparatus 18, the contact plate 54 swings back to the neutralposition 57 due to gravitational forces, as will be discussed furtherbelow. Additionally, a magnetic force from the magnets 74 a, 74 b alsocooperates with the above-discussed gravitational forces to urge theinterrupting vane 70 towards the neutral position.

FIG. 4 b shows a build-up 83 of the ice pieces 38 along the ice chute 16when the ice storage area is full. More specifically, a relatively highnumber of ice pieces 38 are prevented from entering the ice storage areaand become stacked upon each other underneath the contact plate 54,thereby actuating the contact plate 54 further forward into a secondposition 84. When the contact plate 54 and the interrupting vane 70 arein the second position 84, the interrupting vane 70 is positionedbetween neither of the magnets 74 and the sensor elements 76 of thesensor device 72, thereby maintaining the open state of the first sensorelement 76 a, opening the second sensor element 76 b, and indicating tothe controller 78 the position of the contact plate 54. In thisposition, the interrupting vane 70 defines a second angle 86 with thevertical direction that is greater than the first angle 82.

After the build-up 83 of the ice pieces 38 has been removed, the contactplate 54 swings back to the neutral position 57 due to the gravitationaland magnetic forces. However, the build-up 83 is typically not removeduntil some or all of the ice pieces melt or until some of the ice pieces38 have been removed from the ice storage area, such as during icedispensing. The latter of the two events is more preferable and morelikely to occur due to the relatively cold temperature within thehousing 45.

The second end portion 68 of the rod 56 includes a counterweight 88 forbalancing the weight of the interrupting vane 70. More specifically, thesensor element 70 and the counterweight 88 have generally equal weightsto prevent the end portions 66, 68 of the rod 56 from being urged out ofthe saddles 60. Additionally, the counterweight 88 may be designed torotationally counter the weight of the interrupting vane 70 to urge thecontact plate 54 into the neutral position 57 (FIG. 2). For example, thecantilevered nature of the counterweight 88 creates a rotational torqueon the rod 56, the contact plate 54, and the interrupting vane 70 tourge the contact plate 54 into the neutral position 57. Morespecifically, as shown in FIG. 4 a, when the contact plate is in thefirst position 80, the counterweight is in a first position 92 and urgesthe contact plate 54 into the neutral position 57. Similarly, as shownin FIG. 4 b, when the contact plate 54 is in the second position 84, thecounterweight is in a second position 94 and also urges the contactplate 54 into the neutral position 57.

Although unnecessary, a trough 96 is preferably formed in the housing45. This matches the trough in the sensor device 72 on the opposing sideof the housing 45 through which the interrupting vane swings, tosimplify tooling of the manufacturing machines. In this manner the samepart can be molded for both sides, although magnets and sensors areadded only to the sensor element 72.

The ice sensing apparatus 18 may alternatively be an electronicapparatus, such as an optical sensor, an infrared sensor, or any othersuitable device. As another alternative design, an alternative sensorelement may be coupled with the above-described, mechanically actuatedice sensing apparatus 18, such as an optical sensor element to determinethe position of a mechanically actuated plate. In yet anotheralternative design, the ice sensing apparatus 18 includes a single pairof sensor components, such as a single magnet 74 and a single sensorelement 76 that detect the position of the interrupting vane 70. In thisdesign, the ice sensing apparatus 18 may not be able to determine theextent of rotation of the interrupting vane 70, but it may determine theduration that the interrupting vane 70 is held in the rotated state. Theduration of the plate displacement is particularly useful because theplate displacement caused by the migration 79 of the ice pieces 38typically occurs for a shorter duration than the plate displacementcaused by the build-up 83 of the ice pieces 38. Therefore, thecontroller 78 can typically determine which condition (normal icemigration 79 or ice build up 83) is occurring based on the duration ofthe plate displacement.

The water reservoir 26 includes a first mechanism for controlling thewater level in the water reservoir 26 and a second mechanism fordeactivating the ice forming apparatus 12 if the water level is below apredetermined threshold. For example, as shown in FIGS. 6-8, the waterreservoir 26 includes a float valve 100 configured to control a volumeflow of water into the water reservoir 26 and a water level sensor 102configured to detect a water level within the water reservoir 26.

The float valve 100 is a mechanically-actuated float valve having afloating element 104, a valve 106, and an attachment arm 108 extendingtherebeween. When the floating element 104 is positioned at or above apredetermined height within the water reservoir 26, the arm 108 causesthe valve 106 to be in a closed position (as shown by the floatingelement 104 drawn in the phantom line in FIG. 7). If the floatingelement moves below the predetermined height, the arm 108 causes thevalve 106 to move into an open position, thereby permitting water toflow into the water reservoir 26.

The water level sensor 102 is electrically connected to the controller78 to deactivate the ice forming apparatus 12 if the water level in thewater reservoir 26 drops below a predetermined level. The water levelsensor 102 includes a floating element 110 having a magnet coupledthereto and a guide arm 112 connecting the floating element to a reedswitch 114. The reed switch 114 detects the position of the magnet onthe floating element 110 to determine a threshold water level within thereservoir 26. The water level sensor 102 is configured to open anelectrical circuit, indicating to the controller 78 that the water levelhas dropped below a predetermined level (as shown by the floatingelement 110 drawn in the solid line in FIG. 7). However, if the waterlevel is above the predetermined level (as shown by the floating element110 drawn in the phantom line in FIG. 7), then the water level sensorwill close the electrical circuit. When the electrical circuit is open,the controller 78 preferably waits 20 seconds before shutting down, asis discussed in more detail below.

If the water level in the water reservoir 26 is undesirably low, or ifthe water reservoir 26 is empty, the ice making chamber 26 may notreceive a sufficient amount of water to make ice. Additionally, the lackof water in the ice making chamber 20 may cause the chamber temperatureto drop to an undesirable level; thereby causing damage to the iceforming apparatus 12. For example, if no water is present in the icemaking chamber 20, the temperature therein will become too cold and thewalls of the ice making chamber 20 may be permanently deformed; therebypreventing an effective scraping contact between the auger 30 and thewalls of the ice making chamber 20 and potentially damaging the auger30.

The water reservoir 26 also includes an overflow tube 116 that divertswater if the reservoir 26 is overflowing. More particularly, theoverflow tube 116 includes a stand-up portion 116 a that extends intothe water reservoir 26 by a predetermined distance. The predetermineddistance is preferably greater than the normal operational water levelin the water reservoir 26, such that when the float valve 100 isfunctioning properly the water level is below the top of the stand-upportion 116 a of the overflow tube 116.

Furthermore, the water reservoir 26 includes a drainage tube 118 fordrain water from the water reservoir 26 when desired. For example, whenperforming maintenance on and cleaning of the ice making machine 10, itmay be desirable to drain the water from the system. During normaloperation of the ice making machine 10, a water dump solenoid valve (notshown) closes the drainage tube 118 to maintain the desired water levelwithin the water reservoir 26.

Referring to FIG. 5 a, a method 120 of controlling an ice making machinewill now be discussed. During an initial start-up operation 122, the icemaking machine 10 is activated and a start-up operation timer located inthe controller 78 resets and restarts in step 124. Next, in step 126,the controller 78 inputs signals from the first sensor element 76 a todetermine whether the interrupting vane 70 has been displaced forwardinto the first position 57. In other words, the controller 78 isdetermining whether ice pieces 38 are being produced by the ice formingapparatus 12. If no ice is formed for a start-up time period of eightminutes, during step 127, then the ice making machine 10 is deactivatedand switched into a safety shutdown mode in step 128, as will bediscussed in further detail below. During the start-up time period, ifan error has occurred with the formation of ice, the ice formingapparatus 12 typically does not undergo serious damage to the auger 30or the auger motor during the first eight minutes of operating underthis failure condition. More specifically, upon start-up, thetemperature in the ice forming apparatus 12 is typically warm enoughsuch that water in the ice making chamber 20 will likely not freeze intoa solid block during the first eight minutes after start-up. Therefore,the eight minute time period is typically a safe start-up time period.However, in other configurations the start-up time period may be varied.

However, if no water is present in the ice making chamber 20 duringstart-up, the eight minute start-up time period may be long enough tofreeze the walls of the ice making chamber 20; thereby causingdeformation of the walls. Therefore, if the water reservoir has anundesirably low level, the controller 78 will preferably shut-down theice making machine 10. For example, as mentioned above, once thecontroller 78 is signaled that the water level is below a predeterminedlevel, the controller 78 will wait 20 seconds before switching intosafety shutdown mode. However, if the water level rises to or above thepredetermined level during the 20 seconds, the controller 78 will resumenormal operation.

Once the first sensor element 76 a indicates the production of ice, theice making machine 10 enters a normal mode of operation in step 129 andresets and restarts the normal operation timer in step 130. During thenormal mode of operation 129, the controller 78 continues to inputsignals from the first sensor element 76 a to determine whether theinterrupting vane 70 has been displaced forward into the first position57 in step 132. If no ice is formed for a predetermined time period,then the ice making machine 10 is deactivated and switched into a safetyshutdown mode in step 128, as will be discussed in further detail below.The term “predetermined time period” refers to a time period that isdetermined anytime before the predetermined time period begins. Forexample, the predetermined time period may be a fixed time period thatis programmed into the controller. As another example, the predeterminedtime period may be a variable time period that is calculated by thecontroller.

The predetermined time period in the embodiment shown in FIG. 5 a is avariable activity window time period that is calculated by thecontroller based on recent ice activity. If no ice is detected duringthe variable activity time period, during step 131, then the ice makingmachine 10 is deactivated and switched into a safety shutdown mode instep 128. For example, the variable activity window time period isperiod of time ranging from a minimum of 90 seconds up to a maximum of135 seconds that varies based on recent ice making activity. Morespecifically, if the previous X number of ice pieces have been detectedat relatively long time intervals, such as 80 seconds between therespective displacements of the contact plate 54, then the activitywindow will likewise be relatively high (where the variable “x” is a setnumber programmed into the controller). However, if the previous Xnumber of ice pieces have been detected at relatively short timeintervals, such as 20 seconds between the respective displacements ofthe contact plate 54, then the activity window will likewise be equal to90 seconds.

If ice is formed during the normal operation time period, then thecontroller inputs signals from the second sensor element 76 b todetermine whether the interrupting vane 70 has been displaced into thesecond position 84 in step 134. In other words, the controller inputssignals to determine whether a build-up of ice pieces 38 has occurred.If the build-up has occurred, then the ice making machine 10 isdeactivated and switched into a full bin mode in step 129, as will bediscussed in further detail below. If no build-up has occurred, then thenormal operation timer will be reset and restarted. Therefore, duringthe normal operation of the ice making machine 10, the ice formingapparatus 12 will be active until no migrating ice piece 38 is able todisplace the contact plate 54 for a time period equal to the activitywindow or until the build-up 83 of ice pieces 38 occurs.

Although the flowchart in FIG. 5 a shows step 134 occurring only afterstep 132 occurs, in an alternative embodiment the controller immediatelyswitches the system into the safety shutdown step 129 as soon as theelectromagnetic field associated with the second sensor element 76 b isopen, regardless of the timing of the disruption with respect to the icemaking operation.

Referring to FIG. 5 b, the safety shutdown mode 128 will now bediscussed. Generally, upon a system failure, the controller 78 willdeactivate the ice making machine 10. The controller 78 will thenrepeatedly attempt to restart the ice making machine 10 until theexpiration of a primary time period. The primary time period permits thecontroller 78 to attempt a limited number of restarts so that the systemis able to overcome naturally solvable problems, such as a lowevaporator start-up temperature, but is not permitted to perpetuallyattempt to overcome problems that require maintenance or otherintervention, such as a failed or an undesirably low water supply.

After a system failure, the ice making machine waits for a secondarytime period before attempting to restart the ice making machine 10. Thissecondary time period will provide the ice making machine 10 with anytime necessary to overcome the above-mentioned naturally solvableproblems.

As shown in FIG. 5 b, in step 136 the controller 78 determines whether arestart indicator signal is equal to yes. If the restart indicatorsignal is equal to yes, then the ice making machine 10 has beenrestarted recently and the primary timer should continue to run ratherthan being reset and restarted in step 137. In other words, if therestart indicator is equal to yes, then the primary timer shouldcontinue to run without being reset. However, if the restart indicatoris equal to no, then the ice making machine 10 has not experienced afailure recently and the primary timer should be reset and restarted.

Next, in step 138, a secondary timer resets and restarts regardless ofwhether the ice making machine 10 has been restarted recently. Asmentioned above, the secondary timer calculates an appropriate waitingperiod before attempting to restart. More specifically, during step 140,a secondary time period is randomly determined. For example, apredetermined base waiting period (such as eight minutes) is added to arandom time period (such as any integer between 0 and 52 minutes) todetermine the secondary time period. Once the secondary time period iscalculated, during step 142, the controller will continuously determinewhether the secondary time period has expired.

The random secondary time period may be advantageous to improve theefficiency of the ice making machine 10 by having less “down time” dueto system errors. Many system failures may be self-correcting with thedeactivation of the ice making machine 10. For example, if the ice inthe ice making chamber 20 becomes too thick and prevents rotation of theauger 30, the ice will melt during a certain period of deactivation.However, it is often impossible for the controller to predict therequired duration of this period of deactivation; thereby leading to thepossible scenarios where the deactivation period is too short and theice will fail to sufficiently melt and where the deactivation period istoo long and the ice making machine 10 is unnecessarily sitting idle.Therefore, the random secondary time period results in a series ofvaried deactivation periods over a series of shutdowns, possiblyresulting in an ideal deactivation period.

Once the secondary time period has expired, during step 144, thecontroller determines whether the primary timer has been running for athreshold amount of time, such as

300 minutes. As mentioned above, if the primary timer has been runningfor the threshold amount of time, the ice making machine 10 willshutdown completely in step 146 and cease automatic restarting attemptsuntil the system is manually restarted by a technician. However, if theprimary timer has not been running for the threshold amount of time,then the system will set the restart indicator equal to yes in step 148and restart the system in step 150, thereby returning to step 122 inFIG. 5 a. When the primary timer has expired and the ice making machine10 enters shutdown mode 146, the restart indicator is automatically setequal to “NO” in step 145 so that the ice making machine 10 will notregister a recent restart event after the system is manually restarted.

The ice making machine 10 is further capable of operating in variouscontrol modes. Generally, in a preferred design, the modes are asfollows: startup mode, normal ice mode, clean mode, safety shutdownmode, bin full mode, and off mode.

Generally speaking, the startup mode is the mode when power is appliedor reapplied, commonly referred to as P.O.R. If a bypass switch is notdepressed during this state, then a five minute delay is enforced priorto moving to the next state. The purpose of the five minute delay is toprotect the auger drive gear system 35 and the compressor 11. Forexample, if the water in the ice making chamber 20 happened to have beenfrozen to a point that the auger drive gear system 35 would be damaged,this time period will allow the ice to melt. Also, if the ice makingmachine 10 was running when power was interrupted, the evaporator andthe refrigerant stored therewithin may still be cold upon reapplicationof power. If the relatively cold refrigerant is allowed to enter thecompressor 11, the compressor 11 may be damaged. Therefore, the fiveminute time delay allows the evaporator to warm up naturally and allowsthe liquid refrigerant to change into a gas state before entering thecompressor 11.

During startup mode of the ice making machine, startup mode occurs if atoggle switch is in the “Ice”(on) position and the sensor elements 76 a,76 b are both closed. The toggle switch is a manually operated switchthat allows the end user to switch the ice making machine 10 betweendifferent modes (ice making mode, off mode, and clean mode). The controlverifies the water-sensing switch is closed, after which the gear motorstarts immediately. After a five second delay the compressor and fanmotor start.

If the unit is in a restart situation, where the unit stopped due to anopen second sensor element 76 b, a five-minute time period must be timedout prior to starting. After the five-minute time period, if the controlverifies that the following conditions are present then the gear motorstarts immediately: the first sensor element 76 a is closed, the offtime is less than 30 minutes, and the water-sensing switch is closed.After a five second delay the compressor and fan motor start. The waterdump solenoid is energized for 30 seconds and then de-energized, therebyopening and closing the drainage tube 118 to flush the water reservoir26 and provide fresh ice making water. After the water sensing switchrecloses, the compressor and fan motor start.

For both a nugget ice machine and a flaked ice machine, during a powerinterruption restart (if the unit stops due to a power interruption),upon restoration of power the unit will have a five-minute time delaybefore the startup sequence is initiated. During the time delay, asignal, such as a bank of LEDs, will flash. The time delay will bebypassed if the bypass switch is pressed. The control board may haveseven LED's, which function as follows:

-   LED #1: NUGGET—Color RED, will indicate the control is configured    for nugget ice machines when illuminated.-   LED #2: FLAKER—Color RED, will indicate the control is configured    for flaked ice machines when illuminated.-   LED #3: HES#1—Color GREEN, will work in conjunction with Hall Effect    Switch #1.-   LED #4: HES#2—Color GREEN, will work in conjunction with Hall Effect    Switch #2.-   LED #5: CLEAN—Color YELLOW, will indicate the unit is in a clean    sequence when illuminated.-   LED #6: MAINT—Color RED, will indicate that maintenance is required.    This LED is only used when the control is configured for a nugget    ice application.-   LED #7: WATER OK—Color GREEN, will work in conjunction with the    water-sensing switch, when thee switch is closed, (adequate water to    operate), the light on, when the switch is open the light is off.

During normal operation mode, as described above, the ice dischargedfrom the evaporator will intermittently contact the ice contact plate 54as it falls into the bin. The control will see intermittent opening andre-closing of the first sensor element 76 a: this is used to determinethat the unit is functioning normally. During the first eight minutes ofoperation, the control must see at least one opening and re-closing thefirst sensor element 76 a. After the first eight minutes of operationthe control must see at least one opening and re-closing of the firstsensor element 76 aduring the activity window. If the control fails tosee this opening and re-closing of the first sensor element 76 a, theunit goes into a safety shutdown mode as described below. If at any timeduring normal operation the water sensor switch stays open for 20continuous seconds, the unit goes to a safety shutdown mode as describedbelow, and a “WATER OK” LED will flash.

At any point in the operation, if the second sensor element 76 b isopen, the unit goes into the full bin mode. In the shutdown mode, thecompressor/fan motor and the gear motor are de-energized immediately.Once the unit stops, it must remain off for five minutes before it isallowed to restart as described above. During the shutdown period, theLED associated with HES#2 will flash indicating a full bin condition ifthe second sensor element 76 b is active.

In order to determine when the system is to be cleaned, a timer monitorsand tracks the time (in hours) between clean or flushing activities. Onpower up, this timer is set to zero. After each hour of operation, thetimer is incremented. The exception is that during the “random timeout”as described in the SAFETY SHUTDOWN MODE, the timer IS NOT incremented.The cleaning sequence listed below can be initiated if the Ice(on)-Off-Clean toggle switch is placed in the “Clean” position. A cleansequence can also be initiated automatically. When the Clean Timerreaches 50 hours, the unit will stop making ice and go through a cleansequence as described below, and goes back to ice making. The CleanTimer is reset to zero. If a clean cycle is manually initiated by thetoggle switch, the Clean Timer is also reset to zero.

During the clean mode, the yellow LED, CLEAN, on the control board isilluminated. The water sensor switch will open and close during a cleansequence; this is normal and should be ignored by the control. The timeperiods and component operation during a clean cycle are provided byTable 1. TABLE 1 Water Time Evaporator Dump Refrigeration (Minutes) GearMotor Solenoid Compressor Comments 0.00-0.75 Off On Off Dump  0.76-10.00On* Off Off Wash (add cleaner) 10.01-10.75 On On Off Dump 10.76-12.75 OnOff Off Rinse 12.76-13.50 On Off Off Dump 13.51-15.50 On Off Off Rinse15.51-16.25 On On Off Dump 16.26-18.25 On Off Off Rinse 18.26-19.00 OnOn Off Dump 19.01-21.00 On Off Off Rinse*Gear motor will not turn on until the water level switch is closed.

If the toggle switch is switched from “Clean” to “Off” or “Ice”(on)prior to the completion of the initial 0.75-minute dump cycle, the“Clean” sequence will abort. After the initial 0.75-minute dump cycle,if the toggle switch is turned to the “Off” position, the unit stops,and when the switch is turned to another position, the unit will resumeand completes the clean sequence. If the unit is turned back to the“Clean” position, the unit stops after the sequence is complete. Afterthe initial 0.75-minute dump cycle, if the toggle switch is turned tothe “On” position, the unit completes the cleaning sequence and goes toa startup sequence and starts making ice. If the toggle switch is turnedto “Off” within the first 15 seconds of being turned to “Clean”, thenthe cleaning sequence will be cancelled.

The unit ice making machine 10 goes into a safety shutdown mode if anyof the following occur:

-   -   A. The water sensor switch is open for 20 continuous seconds or        more while the unit is in the normal operating sequence mode:        -   1. If the control senses open water-sensing switch for more            than 20 seconds during a normal freezes cycle, the unit goes            into a safety shutdown mode.        -   2. In the shutdown mode, the compressor/fan motor and the            gear motor are de-energized immediately.        -   3. It must remain off for five minutes no matter the            position of water sensing switch.        -   4. During the five-minute shutdown period, the LED for WATER            OK flashes.        -   5. After the 5-minute shutdown period and the water-sensing            switch is closed, the control initiates startup sequence as            outlined in the sequence of operation.    -   Or    -   B. The Hall-Effect Switch (HES)#1 fails to open and re-close at        least once during the first eight minutes of operation after        start-up or re-start.    -   Or    -   C. The HES#1 fails to open and re-close at least once during any        activity window, after the initial eight minute startup period,        when the unit is in a normal operating mode:        -   1. The unit goes into a safety shutdown mode.        -   2. In the shutdown mode, the compressor/fan motor and the            gear motor are de-energized immediately.        -   3. The control times out for a period of {8 +random [0, 52]}            minutes then tries the restart sequence. In other words, the            time out period is equal to 8 minutes plus a random number            between 0 and 52 minutes.        -   4. During the timeout period the LED for HES#1 flashes if it            is active; else, it will not illuminate.        -   5. During the restart sequence, the dump valve is energized            for 30 seconds, the evaporator gear motor is energized, and            the control waits for the water-sensing switch to be closed            before energizing the compressor and fan motor contactor.        -   6. If safety condition is still detected, the control            generates another random timeout period then tries the            restart sequence again.        -   7. These random restarts will occur until one of the            following:            -   a. a total of 300 minutes from the first safety shutdown                has elapsed and no successful restart has been achieved.                At that time the unit will turn off and will require                manual intervention to restart.            -   b. Within the 300 minutes a successful restart (10                minutes of normal ice-making) is registered. With this                event, the elapsed clock is reset to zero.        -   8. When the unit turns off due to 7 a, the LED for HES#1            flashes until the toggle switch is toggled to “Off” and back            to “Ice”(on).        -   9. If the control is reset in this manner, the board will            flash the problem related LED's if the switch is turned to            the “Off” position at anytime during the first 48 hours            after the reset occurred, after which time the reset is            erased from the memory.

During bin full mode, when the ice chute is full and the bin can notaccept any more ice, the second sensor element 76 b opens and the unitshuts down immediately. After a 5 minute time delay, the unit checks for“full bin” status prior to progressing to the “Restart” mode.

During the off mode, the unit is idle. This mode is entered when theice-off-clean selector switch is in the “Off” position.

In another embodiment of the present invention, the ice storage area isa device for dispensing ice, such as a medical dispenser, which is ableto be used in sanitary applications, such as medical applications inhospitals or the like. More specifically, the medical dispenser ispositioned below the ice making machine 10 and is generally sealed fromthe atmosphere to prevent contamination of the ice located within. Themedical dispenser includes an inlet connected to the storage bin inlettube 53 to receive ice pieces 38 from the ice making machine 10. The icepieces are then stored within a body portion of the medical dispenser,which is preferably a one-piece component made of food grade plastic.

Additionally, the medical dispenser includes an outlet formed in thebody and a dispensing device coupled with the outlet to automaticallydispense ice when indicated by a user. For example, the dispensingdevice may include a sensor for detecting the presence of a user'sdrinking cup (or any other container utilized by the user) or anactuating arm that is to be actuated by the user's drinking cup. Thesensor or the actuating arm will then send a signal (mechanical orelectrical) to an agitator located within the body of the medicaldispenser. The agitator then rotates and forces ice pieces out of thedispensing device and into the user's drinking cup. The dispensingdevice may also include a pivoting door that prevents ice from exitingthe body of the medical dispenser until indicated by a user. Any othersuitable ice storage and/or ice dispensing device may be used with thepresent invention. The dispensing device may also include a blue LEDlight to indicate that the ice making machine 10 is on and to illuminatethe front of the medical dispenser unit for a user.

Referring back to FIG. 10, the auger 30 and the casing 24 of the iceforming apparatus 12 will now be discussed in more detail. A water seal160, a C-clip 162, a bearing bush 164 and the upper bearing 43 arereceived by an upper shaft portion 172 of the auger 30 and arepositioned above the ice cutting head 37 to form a watertight sealbetween the auger upper shaft portion 172 and the ice cutting head 37while permitting relative movement between the respective components 30,37. Similarly, the lower bearing 43, a bearing bush 166, a C-clip 168,and a shaft seal 170 are received by an upper shaft portion 172 of theauger 30 and are positioned below the ice cutting head 37 to form asecond seal and permit relative movement between the respectivecomponents 30, 37. Additionally, a run-on ring 174 and an O-ring 176 arereceived by a lower shaft portion 178 of the auger 30 to form awatertight seal between the auger 30 and the casing 24 and to preventwater from leaking into the auger motor 33. The auger lower shaftportion 178 also includes a key slot 182 that receives a feather key 180to be coupled with the auger motor 33. For example, the lower shaftportion 178 is received within a rotatable sleeve (not shown) of theauger motor 33 and the feather key 180 is received within a slot in thesleeve to rotate the auger 30 when the auger motor 33 is activated.

The above components are received within the casing 24 and are furthersecured therewith by a water seal 184, a C-clip 186, a roller bearing188, a shim ring 190, and a second C-clip 192. More specifically, thewater seal 184 cooperates with the run-on ring 174 to form the lowerseal between the auger 30 and the casing 24. Additionally, the rollerbearing 188 permits relative movement between the auger 30 and thecasing 24 during rotation of the motor sleeve. Additionally, a pluralityof screws 194 are received within openings 195 in the casing and securedto the ice cutting head 37 via threaded openings 196 to prevent rotationof the ice cutting head 37 with respect to the casing 24.

The ice making chamber 20 is preferably manufactured by Ziegra, which islocated in Isernhagen, Germany, and is commercially available as modelnumbers ZNE125, ZNE200, ZNE300, ZNE400, ZNE500, ZNE1000, ZNE200FE,ZNE300FE, ZNE400FE, ZNE500FE, and ZNE1000FE, where the number in eachmodel number indicates the capacity of the ice making chamber 20 inkilograms per hour and the designation “FE” indicates that flaked ice ismade (no designation means that nugget ice is made). The auger drivegear system 35 is preferably a gear system that prevents the auger motor33 from undesirably operating in the reverse direction due to loadspresent on the auger 30 during system startup. The water level sensor102 is preferably a Gems type LS-3 water level sensor manufactured byGems Sensors, which is located in Plainville, Conn.

The above described embodiment provides a low cost, simple design andmethod for detecting the migration of the ice pieces through thetransfer zone and for detecting the build-up of the ice pieces in thetransfer zone. Furthermore, the above described embodiment provides animproved ice sensing apparatus by substantially separating a portion ofthe apparatus from the clean zone and the naturally-occurring moisturelocated therein.

While the invention has been described in connection with an auger-typeice machine, it can also be used with other types of machines, such ascube-type machines, nugget-type machines, or medical dispenser machines.

It is therefore intended that the foregoing detailed description beregarded as illustrative rather than limiting, and that it be understoodthat it is the following claims, including all equivalents, that areintended to define the spirit and scope of this invention.

1. An ice making machine, comprising: a) an ice forming apparatuscapable of forming ice pieces; b) a transfer zone connecting the iceforming apparatus with a storage area so as to permit migration of icepieces from the ice forming apparatus to the storage area; and c) an icesensing apparatus configured to detect at least some of the ice piecesduring the migration of the ice pieces through the transfer zone.
 2. Theice making machine of claim 1 wherein the transfer zone is located withrespect to the storage area so that a build-up of ice pieces occurs inthe transfer zone when the storage area is full.
 3. The ice makingmachine of claim 2 wherein the ice sensing apparatus is configured todetect at least some of the ice pieces during the build-up of the icepieces in the transfer zone.
 4. The ice making machine of claim 3wherein the ice sensing apparatus includes a movable portion having afirst position corresponding to the migration of the ice pieces and asecond position corresponding to the build-up of the ice pieces in thetransfer zone.
 5. The ice making machine of claim 4 wherein the icesensing apparatus includes a first sensor to detect the first positionof the movable portion and a second sensor to detect the second positionof the movable portion.
 6. The ice making machine of claim 4 wherein themovable portion comprises a contact plate positioned along a path of themigration of the ice pieces in the transfer zone.
 7. The ice makingmachine of claim 6 wherein the ice sensing apparatus further includes arod coupled with the contact plate and a signal member coupled with therod, and wherein the contact plate and the signal member are configuredto pivot in unison between a neutral position, said first position, andsaid second position.
 8. The ice making machine of claim 3 furthercomprising a controller in electrical connection with the ice sensingapparatus and the ice forming apparatus, wherein the controller isconfigured to deactivate the ice forming apparatus if the ice sensingapparatus fails to detect the migration of the ice pieces through thetransfer zone during a predetermined time period.
 9. The ice makingmachine of claim 8 wherein the predetermined time period is equal to afirst duration during an initial start-up operation of the ice makingmachine and is equal to a second duration shorter than the firstduration after the initial start-up operation of the ice making machine.10. The ice making machine of claim 9 wherein the controller isconfigured to deactivate the ice forming apparatus if the build-up ofthe ice pieces in the transfer zone is detected.
 11. The ice makingmachine of claim 10 wherein the controller is configured to immediatelydeactivate the ice forming apparatus if the build-up of the ice piecesin the transfer zone is detected.
 12. The ice making machine of claim 1,the ice making apparatus further comprising an auger.
 13. A combinationof the ice making machine of claim 1 and an ice storage bin, the icestorage bin providing at least a portion of said storage area.
 14. Anice making machine, comprising: a) an ice forming apparatus having anoutlet section and being configured to form ice pieces and; b) atransfer zone connecting the outlet section of the ice forming apparatuswith a storage area so as to permit migration of ice pieces from the iceforming apparatus to the storage area; the outlet section of the iceforming apparatus and the transfer zone together comprising a cleanzone; and c) an ice sensing apparatus configured to detect the presenceof ice pieces within the transfer zone, wherein the ice sensingapparatus includes a first portion located within the clean zone and asecond portion positioned outside the clean zone.
 15. The ice makingmachine of claim 14 wherein the first portion of the ice sensingapparatus comprises a contact plate positioned along a path of themigration of the ice pieces through the transfer zone.
 16. The icemaking machine of claim 15 wherein the second portion of the ice sensingapparatus includes a signal member coupled with the contact plate suchthat the contact plate and the signal member are configured to pivot inunison between a first position and a second position.
 17. The icemaking machine of claim 16 wherein the ice sensing apparatus includes asensor for sensing whether the signal member is in the first position.18. The ice making machine of claim 17 wherein the sensor issubstantially separated from moisture in the clean zone.
 19. The icemaking machine of claim 14 wherein the ice forming apparatus includes anauger rotating about an axis within a cooling chamber.
 20. The icemaking machine of claim 14 wherein the ice sensing apparatus isconfigured to detect at least some of the ice pieces during themigration of the ice pieces through the transfer zone.
 21. The icemaking machine of claim 20 wherein the transfer zone is located withrespect to the storage area so that a build-up of ice pieces occurs inthe transfer zone when the storage area is full and wherein the icesensing apparatus is configured to detect at least some of the icepieces during the build-up of the ice pieces in the transfer zone. 22.The ice making machine of claim 21 wherein the first portion of the icesensing apparatus is a contact portion located within the clean zone andthe second portion of the ice sensing apparatus is a non-contact portionseparated from the clean zone by a generally fluid-tight seal.
 23. Amethod of controlling an ice making machine, comprising: a) forming icepieces with an ice forming apparatus; b) permitting migration of the icepieces from the ice forming apparatus through a transfer zone to astorage area; c) detecting at least some of the ice pieces migratingthrough the transfer zone; and d) deactivating the ice forming apparatusif no migrating ice pieces are detected within a predetermined timeperiod.
 24. The method of claim 23 further comprising calculating thepredetermined time period based on a frequency at which the ice piecesare formed.
 25. The method of claim 23 wherein the step of forming icepieces includes rotating an auger about an axis within a coolingchamber.
 26. The method of claim 23 wherein the predetermined time limitis equal to a first time during an initial start-up operation of the icemaking machine and is equal to a second time shorter than the first timeafter the initial start-up operation of the ice making machine.
 27. Themethod of claim 23 further comprising, after the step of deactivatingthe ice forming apparatus, reactivating the ice forming apparatus aftera delay time period.
 28. The method of claim 27 wherein the step ofreactivating the ice forming apparatus includes randomly selecting thedelay time period from a database of potential delay time periods.
 29. Acombination of the ice making machine of claim 1 and an ice dispenserconfigured to dispense at least a portion of the ice pieces formed bythe ice forming apparatus.